TY  - JOUR
AU  - Jan Persson
TI  - Non-Uniqueness and Uniqueness in the Cauchy Problem at Simple Characteristic Points.
JO  - Mathematische Annalen
PY  - 1973
SP  - 231
EP  - 238
VL  - 203
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAN_1973__203_162444/
ID  - MAN_1973__203_162444
ER  -